private void listBox1_MouseMove(object sender, MouseEventArgs e) { if (DragOn) { if (dragBoxFromMouseDown.Contains(e.X, e.Y)) { return; } if (LB.SelectedItem == null) { return; } LB.DoDragDrop(LB.SelectedItem, DragDropEffects.Move); DragOn = false; lbLine.ClearLine(); } }